Boiler



March 8, 1932.

A. KRIER ET AL BOILER Filed April 11, 1931 Patented Mar. 8, 1932v p terse; earns ADOLPH"KRIER AND JOHN B. KRIEB, OF CHICAGO, ILLINOIS, ASSIGNORS TO 'KBIER BOILER COMPANY, OF CHICAGO, ILLZ NOIS, A CORPORATION OF ILLINOIS BOILER Application filed April 11,

functional, in boilers and heating appliances,

employedtoydesignatethe same structural one leading object being to provide a construction or heating apparatus of this character which shall be strong structurally,

which shall be simplein design, which can be manufactured at comparatively low cost,

which Will possess long life, and which will be eificientin operation. 7

v To ithis end, especlally'in relation to its efliciency in action,'the boilerrisconstructed to take advantage of the thermossiphon ac-r,

tionof the heatedwater and theparts of the 7 structure are so arranged and combined to render the boiler, in large me automat c cleaning. I

To theaccomplishment of these and other desirable aims and objects of the'invention,

asure,self or we havedevised its present, preferred embodiment which is illustrated in the acco-mpanying drawings, forming a part of this specification," andto which reference should be had in connection with thefollowing detailed description. p i

For simplicity, in theseveral views of the drawings, likere'ference characters have been parts.

In these drawings: v a

Figure 1 is a longitudinal, (vertical, central section through the improved "boiler 'on line 1'-1 of Figure 2; V

Figure 2 is'a vertical cross-section of the construction on line2- 2 of Figure 1; and

.Figure 3 is a similar cross-sectionon line 7 33 of Figure 1Q plates 12,12defining and enclosing an ash pit 13'and supporting agrate. 1 L ofany usual or appropriate construction, includes an outer metal shell com JIlSlIl a curved top15- and vertical sidewalls 16, 16, suclrouter sheil having a front, flangedhead. or wall 17 and a corresponding .flanged back head or wall 18, both of which may be riveted or welded 1981. Serial N0. 529,344.

to the curved plate forming the other portion of the outer shellor casing.

As is presented in Figure 1, these end heads or walls are further secured in position and the structure as a whole stifie'ned and fortified by stay-rods l9 fastening them to the main sheet of the outer casing. I I

Inside of such outer shell is an inner shell or casing forming a relatively-long," main combustion-chamber 21, which, at its rear end, connects directly with a back, supplemental or auxiliary combustion-chamber 22,

which extends above the crown-sheet of the I main-chamber," such upper-"part of the rear chamber connecting with and communicating with forwardly-extended fines or tubes 23 which reach to the front of the boiler.

Such main or principal combustion space o lSfOlll'lQd by a single metal sheet bent to proride the upwardly-arched, desirable semi-,

cylindrical, crown-sheet 24 and depending side-walls 25, 25 which are spaced inwardly away from the'coinpanion, outer walls l6, l6

to provide side water-legs 26,26.

The front end of such inner shell is provided with a flanged head or end-wall 27 lo cated inwardly awayfrom the complementary,"outer-shell end-wall 17, thereby supplying a front water-leg 28.

As is shown inFigure 1, the front of the boiler is equipped with a closure 29 for the ash-pit fitted with a suitable door giving ready access to the, ash-pit, with a firebox doorway and its associated door 31 leading to the fire-box, and. with a' smoke-box 32 with which the front ends of theflues -23 connect staclror chimney through the exit or dis charge opening 33 in its top l p l The sheet-metal side-walls 34, 34; of the higher chamber 22 may be integral with the side-walls 25, 25gof the main combustionchainber, or they may beseparate plates with their front edges riyeted or welded tofthe rear edges of the plates25,"25,the side waterlegs between the inner and outer shells ex tending the full height of 22 at those points} I I A flanged head or rear end-wall 35 closes the back end of the internal shell and an aper and which is adapted for associationwith the I such rear chamber w tured flue-plate 36 is present between the crown-sheet 24 of the main chamber, the top wall of the auxiliary chamber, and the sidewalls of the latter, such flue-plate forming an integral section of one of the plates or constituting a separate element riveted or welded in place.

A hollow, water-filled bridge-wall 37, formed of separated side-plates 38, 38, a flat, bottom plate 39 and a bent, top plate 41 extends from side-wall to side-wall of the combustion-chamber just to the rear of the grate 14 and the ends of its four plates 37, 38, 38, 39 project into properly-shaped apertures in the plates 25, and are welded around their borders.

As is clearly depicted in Figure 2, the top plate 41 of such bridge-wall slopes upwardly in opposite directions from its center, whereby to facilitate the upward flow of heated water therebeneath into the side waterlegs of the boiler with which the interior of the wall is directly connected.

In order to strengthen the bridge-wall, if required, it may be provided with a suitable number of stay-bolts 40.

In the fire-box above the grate 14, the boiler is provided with a hollow, water-filled smoke arch or bafile 42 of almost semi-circular form and com osed of sheet-metal side-plates 43, 43 with t eir edges conforming to the curvature of the crown-sheet 24 and a sheet-metal bottom plate 44, which if preferred, may com rise a flange on one of the side-plates wel ed along its free edge to the bottom of the companion side-plate. V

The crown-sheet 24 is cut out to receive the curved or rounded edges of such side-plates 43, 43 which are welded to the margins of such opening, so that the interior of the smoke-arch is in direct communication with 7 deep and, therefore, connects together the two side water-legs of the boiler, as well as being in communication with the water space above the crown-sheet, and this arch has no tubular passages through it corresponding to the fee parts 45, but owing to its greater size, its sidewalls are tied together by stay-bolts 47, 47.

An understanding of this construction will show that it has an extra large fire-box and combustion-chamber which are surrounded at both sides, front, top and rear with wide water spaces, providing for a great amount of direct and effective heating surface and allowing the combustion gases to expand adequately and to complete their combustion fully before entering the boiler tubes or flues;

boiler and a more even or uniform temperature of the water throughout the boiler, such water circulation drawing the water from the cooler water-legs and carrying it effectively into the more highly heated portions of the boiler.

These water-filled cross-members also mechanically tie together the side-walls of the boiler, assisting in preventing their distortion or bulging, and the front and rear ones are spaced in such a manner as to effectively stiffen and strengthen the crown-sheet, hence eliminating the necessity for radial stays for such sheet, the employment of which would preclude the most desirable arrangement and disposition of the tubes or flues.

Due to the fact that the crown-sheet is arched upwardly, it promotes efiicient combustion and it is self-cleaning in that it prevents scale and sediment accumulation on its surface and thus maintains its ready and able heat transfer to the water.

The bottoms of the several water-1e s may be closed in any appropriate manner y the use of a flange on one of the two plates which is welded to the opposite plate.

The plate sections or portions 24, 25, 34, 34 of the inner shell are fastened to the side-walls of the outer shell by horizontal stay-bolts 48, 48 of different lengths, and the top wall of the back combustion-chamber '22 is secured to the top of the outer shell by vertically-disposed stay-bolts 49.

Horizontal stay-bolts 51 extend between some of the fiues 23 and secure together the side-walls of the outer shell above the crownsheet, all as is clearly illustrated.

It will be clear from the illustration of the boiler that the smoke-arch extends downwardly below the top of the bridge-wall and that the combustion-chamber arch projects downwardly a substantial distance below the top of a bridge-wall, such three members forming a tortuous passage for the gases which will causethem toco-mingle to secure their more complete combustion and will result in their intimate contact with the various heating surfaces of the boiler, whereby to give the latter a satisfactory economy of operation.

. The invention as presented in the appended claims is not limited and restricted to the precise and exact details of structure shown and described, but is susceptible of a variety of embodiments varying more or less in structuralaspects but all incorporating the fundamental principles of the invention.

Stated somewhat differently, more or less major or minor modifications may be made in the boiler set forth, without departure from the heart of the inventionand without the loss 'or'sacriiice of any of its material benefits and advantages.

We claim:

1. In a boiler, the combination of an outer sheet-metal shell, an inner sheet-metal shell forming a main combustion-chamber and a supplemental combustion-chamber to therear'of, communicating with, and extending higher'than said mainchamber,'said inner shell being spaced away from said outer shell at'all points to provide side, front and rear water-legs and being curved upwardly at the top of said main-chamber to provide a crown-sheet therefor, flues above said crown-sheet and connected at their rear ends to the upper portion of said supplemental combustion chainber, a hollow bridge-wall to the rear of said'grate having the endsof its interior directly connectedto'theinterior of the opposite side water-legs, thetop of said bridge-wallsloping upwardly and outwardly in opposite directions from its center,

a hollow smoke-arch depending from said crown-sheet above said grate suliicicntly to overlap at least a portion of said; bridgewall andhavingits top and ends opening through said'crown-sheet to the water space above, and a hollow combustion-chamber arch depending from said crown-sheet to the rear of saidbridge-walland extending down below the top of said bridge-wall, said combustion-chamber arch opening at its top and ends through said crown-sheet and through said inner-shell side-walls into said side water-legs.

2. In a boiler, the combination of an outer o rear water-legs and being curved upwardly at the top of said main-chamber to provide a crown-sheet therefor, flues above said crown-sheet and connected at their rear ends I to the upper portion of said supplemental combustion-chamber, 'a grate in the front part of said main combustion-chamber, a hollow, bridge-wall to the rear of said grate having the ends of its interior directly connected to the interior of the opposite side water-legs, a hollow smoke-arch depending fromisaid crown-sheet above said grate sufour hands.

ficiently to overlapat least a'portionof said I bridge-wall and having its top and ends opening through said crown-sheet, and a 1101- low combustion-chamber arch depending from said crown-sheet to the rear of said bridge-wall and extending down below the top of said bridge-Wall, said combustionchamber arch opening at its top and ends through said crown-sheet and through said inner-shell side-walls into said side waterlegs.

3.. In a boiler, thecombination of an outer sheet-metal shell, an inner sheet-metal shell forming a main combustion-chamber and a supplemental combustion-chamber to the rear of, communicating with, and extending higher than said main-chamber, said inner shell being spaced away from said outer shell at allpoints to provide side, front and rear water-legs and being curved upwardly at the top of said main-chamber to provide a crown-sheet therefor, fines above said water-legs,a hollow smoke-arch depending from said crown-sheet above said grate and crown-sheet, and a'hollow combustion-cham- So I having its topand ends opening through said.

berr arch depending from said crown-sheet to the rear of said bridge-wall and opening at its topand ends through said crown-sheet and through said inner-shellside-walls into said side water-legs.

In witness whereof we have hereunto set AD'OLPH KRIER; JOHN B. KRIER. 

